Stone-saw.



W. F. MEYERS.

STONE sAw.

Patented Deo. 7, 1915.

APPLICATION FILED MAR. 20| 1915.

WiLLaRii F. Mnirnns, or LONG isLANnoirY, Yoan.

sroNn-SAW. n

incasso.

Specification of Letters Patent.

rateale-ea nee. '7, isis.

Application filed March 20, 1915. Serial No. 15,840.

To all whom 'it may concern: f

Be it known that l, VVILLARD F. Mnrinzs, a citizen of the United`States, residing at Long lsland City, in the county of Queens andState'of New York, liave'invented cer f tain new and useful Improvementsin Stone- Saws, of which the following is a specification, referencebeing had therein to the accompanying drawings, forming part thereof.

My invention relates to stone sawsof the ftype in which abrasivematerial, such as carborundum, for example, is employed to forni thecutting edge or cutting face ofthe saw.

Heretofore much trouble has been encountered in sawing ystone withcarboruny dumor other abrasive material, due to the fact that theabrasive cutting edges or cutytingffaces wear off moreat the corners ormargins than along the middle, so that the cutting faces soon becomerounded, with the result in use that these roundedcorners chipor breakthecorners of the stone, particularly where the moving saw leaves thelrei'f. y f I 4My invention has for its prime object not only to`overcome this `difliculty and to `cause the abrasive .cutting vedgesoiworking faces to wear away, rsubstantially equally in their middlevandinarginalportions so as torpr'esent asubstantially straight transversesurface with comparatively sharp corners, buty to cause the cuttingfaces to wear 'to a transversely hollow or longitudinally groovedcontour presenting marginal `longitudinal ridges, whenso desired, as afurther preventive of chipping the corners of the stone.

More particular objects and advantages of myinvention will hereinafterappear.

My invention includes providing `a cutting` face of abrasive materialhaving a longitudinal series of weaiproducing or wearproviding breaksorgaps in the abrasive niaterial along the middle of the rcutting face,more particularly, these breaks or gaps being provided by va series ofholes, for causingy the ,abrasive material at the middle transversely ofthe ycutting face to 'Wear away, as fast or faster than the corners ormargins, and preferably these wear-produc- 'iig holes containstrengthening coresofsoft material.u f

My invention also includes features 4,of construction and combinationsof`parts,as will appear from the following description.

)l :shallnow describey the embodiments of my'finvention illustrated inthe-accompanyrsive teeth.

ing drawingsand shall thereafterpoint out my invention in claims.y

Figure l is a plan of the upper partl of a circular rotary abrasivesawfembodying my invention. Fig. 2 is a longitudinal vertical section ofthe same on a plane indicatedby the line 2 2 of Fig. rl as .viewed fromvbelow. Fig.' 3 is a transversevertical section of the same on a planeindicated bythe line 3 3 `of Figs. l and 2 as viewed from the right.Fig. l is a similar view after use and wear. Figo isa plan similar toFigflofa modified embodiment of my invention kas compared with thatillustrated in the preceding figures.y Fig. 6 is a longitudinal' Fig. 9is a vertical section of the same on a Y plane indicated by the line 9 9of Figs. 7 and 8.k Fig. 10 is a plan or View looking toward the cuttingVface of an abrasive Vsaw tooth `adapted to be mounted on a metallic sawblade and embodying my invention. Fig. 1l is a Vertical centrallongitudinal section of the saw tooth of Fig. 10. Fig. l2 is a verticaltransverse `section of the same through ione ofthe wear-producing holes.Fig. 13 is a view similar to Fig. 4i and illustiatesliovv "abrasiverstone saws as heretofore commonly constructed wear to an objectionablyrounded contourk at the cutting face.

l My invention is equally applicable` to stone saws formed of abrasivematerial and to those having a metal blade carrying abraln Figs. 1, 2, 3and l of the drawings, my invention is shown as embodied in a ycircularrotary stone saw. l formed of a wheel of abrasive material, such kascarborundum,

yprovided'originally with a transversely straight cutting face havingrsharp square corners, as appears inFigs. l, 2 vand 3. A longitudinalseries of wearproducing holes o is provided in the abrasive materialalong the middle of thejabrasive cuttingface. The ywear `producinglholes a areshown as'r arranged radially Vofthe saw l -or perpendicularto kits `cutting face, and are of uniform,

dle of thecutting face. f i l rlhe wear-producing-holes a are arrangedin staggered orizig-zag relation and contain size and equidistantlyspaced along the midsoft strengthening cores gor plugs 'o of softmaterial. These strengthening cores b may be composed of any suitablematerial, such as carbon or" a suitable degree of softness, hard rubber(vulcanite), sticks of baked shellac or other binder, or a suitablemetal, for example, aluminum. The cores b are molded into the abrasivematerial of the saw l and the bond or binder of the abrasive materialbecomes amalgamated with or firmly adheres to the cores so that thecores are tirmly attached to the surrounding abrasive material and serveto prevent any substantial impairment of the strength of the wheel byreason of the wear-holes a, but these strengthening cores being softotter only a slight resistance to wear and serve in this respectsimilarly to the wear-holes fr alone with the cores b. The staggeredarrangement o the wearproducing holes a is also fork the purpose ofmaintaining the strength of the saw, and provides for obtaining a widemiddle groove in the cutting face, with resulting thin or sharp marginalridges by means of holes of smaller diameter than would otherwise berequired for similar results. The abrasive saw l is of homogeneouscomposition, so that its cutting face is of like hardness throughout.rlhe presence .o the wear-producing holes a, containing the soft coresb, increases the wear of use on the middle portion of the cutting taceover what it would be without these corecontaining holes. There are tworeasons for this. First, the reduction in quantity of the harderabrasive material along the middle of the cutting face produced by theholes a and its replacement by the much softer material of the cores b;and second, the edges or corners presented by `these holes at thejunction of the harder and softer materials facilitate wear. f Y

The wear-producing holes a, containing the strengthening but readilywearable soft cores are of a size and so arranged in staggered relationand spaced apart that the increased wear produced by these holes willcause the middle of the cutting face to wear awa)7 'faster than thecorners or lateral margins,lso that after a comparatively short periodof use, the wear will produce a cutting face having thin lateral cuttingedges and a middle groove of llJ-shape, as appears in Fig. 4. It hasbeen found that a cutting face ot' this groove form produces much lesschipping of the corners of the stone than 'does the usual transverselystraight cutting face, which when it becomes rounded at the corners byuse, as indicated in Fig. 13, causes keven worse chipping of the stone.Vith a grooved cutting face, such as appears in Fig. 4, the sharp sideedges or ridges of abrasive material cut the stone in'advance of thecutting done by the middle groove portion, these thin ridges causingvery little chipping or breaking away o the stone outward from thekert', and any chips or broken 0H pieces will be quitesmall, and thesubsequent breaking away of the projecting middle tongue ot' stone leftby the groove of the cutting tace can do no harm as the edges or cornersof the stone aty the kerf are protected by the narrow lateral grooves ofthe kert cuty in advance by the thin projecting lateral ridgesV of thecutting face. renter the cutting face has become thus grooved to acertain depth, further deeper grooving will not take place, because ofthe fact that a balanced condition or" wear will have been reached, forexample, as 'shown in Fig. t. Y

rllhe grooving ol the cutting face along the middle will be more or lesspronounced according to the size of the wear-producing holes a and theirdistance apart. lf the holes a are larger, the grooving oli the cutting:tace will be more or deeper, and it smaller, it will be lessorshallower, so that the desired extent of such grooving, according to theparticular requirements, may be determined and controlled.

In the modifiedA embodiment of my invention illustrated in Figs. '5 and6, wearproducing holes c with contained soft strengthening cores d areprovided along the middle line of the cutting tace ofv a circular rotaryabrasive stone saw 2. The wear-producing holes c and their cores d areof slightly larger diameter than the corresponding holes a, and coresbot the iirst described construction and are all arranged with theiraxes in the same plane at the middle of the cutting Vface instead of instaggered relation. rllhe cutting face with the wear of use will assumesubstantially the conformation illustrated lin Fig. el and hereinbeforedescribed.

By employing smaller wear-producing holes of the proper size and spacingthem farther apart the proper distance, for example, such as the smallerand more widely spaced wear-producing holes e shown along the middleline of the cutting face in the circular rotary abrasive stone saw 3illustrated in Figs. 7, 8' and 9 of the drawings, the abrasive cuttingface may be caused to wear away evenly so as to preserve its originaltransversely straight condition, substantially as appears in Fig. 9, asin some instances might be desirable. Because of the fact that thewear-producing holes e are small and widely spaced, the abrasive saw 3will not be appreciably weakened by these holes and thestrengthening'cores.such as hereinbefore described are omitted leavingthe wear-producing Yholes c open.

Centrifugal force willY tend to keep the open wear-producing holes ctree from cuttings, but as an assistancein this respect, counterbores` fare provided which commuf iso nicate with the wear-producing holes e atthey sides, and these counterbores f are shown as inclined outwardly andentering the holes e at the bottoms of the latter. liquid, such aswater, employed yin sawing stone will flow in at the counterbores f andout through the radial wear-producing holes e, by reason of centrifugalforce, and will assist in keeping the holes c open.

In manufacturing the abrasive stone saw of my invention, theopenwear-producing holes, such as e, and also the counterbores f may bereadily drilled by means of a diamond drill.. facture for openwearfproducing holes, soft cores corresponding to the several holesk maybe molded into the abrasive material of the saw, as hereinbeforedescribed, and then these soft cores removedy byv drilling'v them out.0r in case metal cores are employed, they could be pulled out ifdesired. Should such soft cores be `leftin the holes, my invention wouldbe carried out as hereinbefore described.

It is to vbe understood that the wear-pro ducing holes, either with or.without the ksoft strengthening cores, may be of any depth desired,according to the depth to which the abrasive material is to be worn awayby use,

and in the case of a rotary saw vsome of the holes may be of less 'depththan the others l so as to compensate for the decreasing circumstance asthe center `of theoircular saw wheel 1s approached.

In Figs. 10, l1 andflQ I `have'shown thev application of my invention toseparate abrasive saw teeth adapted to be mounted on a metal saw bladein any suitable way, as is well understood'in the art. The tooth l isformed of suitable abrasive material of homogeneous compositionthroughout, for example, carborundum, and is shown asprovided on itstransversely straight cutting facewith a longitudinal row or series of'wear-producing holes g shown as extending perpendicular tothe cuttingface nearly but not quite through to the base of the tooth andcontaining soft readily wearable reinforcing or strengthening plugs orcores L. The operation is substantially fthe same as hereinbeforedescribed in reference to the wear-producing holes a, @and c.

It is obvious that various modifications may be made in theconstructions shown in `the drawings and above particularly de- Copiesof thisr patent may be obtained for The usual As another method of manufscribed within the my invention.

I claim:

l. A stone saw having abrasive'material providing a cutting face andhavingwean producing holes in such material along the middle portion ofthe cutting face, the marginal portions of the cutting face beingcontinuous and free from such holes, so that fthe Wear of use along themiddle of the principle and scope of y providing a cutting face andhaving a lonn gitudinal series of lwear-producing holes of uniform sizeequidistantly spaced along the middle only of the cutting face.

4. A stone saw having homogeneous abrasive material providing a cuttingface and havinga longitudinal series of wear-producing holes of uniformsize equidistantly` spaced along the middle only of the cutting face andarranged perpendicular to the length of the cutting face.

5. A stone saw having abrasive material providing a cutting face andhaving a longitudinal series of wear-producing holes in the middleportion only of the cutting face, and strengthening cores of softmaterial contained in the wear-producing holes and f ,having firmattachment to the surrounding abrasive material.

6. Al 'stone saw having abrasive mater1al providing a cutting face andhaving a longitudinal series of wear-producing holes in f the middleportion only of the cutting face, the size of these wear-producing holesand the distance between them being such as to produce a predeterminedamount of increased vvear along the middle of the cutting face.

In testimony whereof I have aiiXed my signature in presence of twowitnesses.

WILLARD F. MEYERS.

ve cents each, by addressing the Commissioner of Patents, Washingtom ID;C. g

